How To Optimize Images

Optimize images

To give your brand the best opportunity to succeed with SEO, you should understand the basics of image optimization.

Image optimization is the process of creating and delivering high-quality images in the ideal format, size, and resolution to increase user engagement. It also involves accurately labeling images so search engine crawlers can read them and understand page context. 

Follow this steps to optimize your images:

1. Resize your images

Image size and file size are not the same thing. Image size refers to the dimensions of an image (e.g., 1024 by 680 pixels). File size is the amount of space needed to store it on the server (e.g., 350 kilobytes).

Images with higher resolution and larger dimensions (often created with a professional camera) slow your page load times considerably. While they work well for print reproduction, you need to scale down the file size without losing too much quality for them to work well on the web.

2. Pick the right file format

PNG, JPEG, and GIF are all popular. Each has its benefits. I recommend JPEG for images with lots of color and PNG for simple images.

3. Choose the right compression rate

If you compress an image too much, the file size is small but the image quality is poor. On the other hand, when you use a low compression rate, the image quality is high but the file size is huge.

Ideally, you should experiment with your file types and compression rates to see what works best for each image. Many image-editing tools, including Adobe Photoshop, have a “save for the web” option, which automatically minimizes the file size while optimizing image quality.

If you don’t have Photoshop, here are some popular tools:

Image optimization tools

• Affinity Photo
• Pixlr (JPEG optimization)
• ImageOptim (Mac only)
• Kraken (bulk compression)
• Gimp
• Paint.NET
• JPEG Mini
• OptiPNG
• FileOptimizer
• Trimage

WordPress plug-ins for image optimization

• Yoast SEO
• ShortPixel
• EWWW Image Optimizer
• WP Smush
• TinyPNG
• ImageRecycle
• Optimus Image Optimizer

Test optimization for speed

After you’ve optimized your images, how do you know whether your website page loading times are quick enough? Use one of following tools to test your site speed:

• WebPageTest
• Pingdom
• GTmetrix
• WebWait
• Google PageSpeed Insights

As your website and content change frequently, it’s a good idea to keep checking your stats over time.

4. Optimize image file names

Before uploading any image, name the file with relevant, descriptive keywords to get the most SEO power. Include target keywords at the beginning and separate them with hyphens. Don’t use underscores because search engines don’t recognize them and won’t be able to “see” the words individually. Use hyphens when creating an image file name so search engines can “see” the words. 

5. Use alt tags

Viewers may understand what a picture is about, but search engine spiders still need clues. Without alternative text, it’s impossible for search engines to accurately index your image content. A good alt tag provides context and helps visually impaired users too. Even when images aren’t loading because of a glitch, search engines can still read the alternative text to help rank a page. Brand-relevant words can be included here to boost visibility. Just avoid keyword stuffing.

Provide more detail than you included in the file name. While no ideal number of words exists, aim for 10 to 15 to convey something about the image.

6. Optimize the image title

If you use WordPress, the image title is usually taken from the name of the file so you can sometimes leave it as it is. If you don’t use WordPress or the title doesn’t explain the image, rename it with the appropriate keywords in the same way as file names.

Image titles are less important for SEO, but they can provide additional context to the alt text. Image titles are more helpful in terms of user engagement. Consider adding a brief call to action such as “buy now” or “download today.”

7. Include captions

Image captions – the words directly beneath images – may not have a direct impact on SEO, but, unlike file names and alt text, captions are visible on a website page. For this reason, they can add to the user experience.

Use captions for images to create better user experience (and lower bounce rate)

8. Use unique images

Using stock photos is fine, but they won’t necessarily help your search rankings, as other websites often use the same images. In the same way that unique written content is better for SEO, it’s a good idea to upload unique images whenever possible.

9. Ensure that your text complements the images

The copy on the page can help search engines determine the relevancy of your images. If it doesn’t include enough information to explain an image, add more relevant text, and describe the image if possible.

10. Add image structured data

Adding structured data to your pages helps search engines display your images as rich results. Google Images supports structured data for product images, videos, and recipes. For example, if you have recipes on your site and you add structured data to your images, Google can add a badge to your image showing that it belongs to a recipe.

11. Use site maps

According to Google, a site map is “a file where you can list the web pages of your site to tell Google and other search engines about the organization of your site content.” In other words, it’s a file that contains a map of your site’s content.

Site maps are an important part of SEO because they tell search engines about all the pages of your site. To ensure that search engine crawlers notice every image – an infographic, meme, photo, video thumbnail, etc. – include them in your site map.

For these image map entries, include the title, description, URL location, caption, and license information. For video entries, include the title, description, URL location, thumbnail URL, and raw video file URL.

If your website is hosted on WordPress, you can use Yoast SEO, which will automatically add your visual content to a site map.